Carpets, rugs, mats, and like floor coverings used in home and industrial applications are typically made from natural fibers (such as cotton and wool) or synthetic fibers (such as nylon, polyester, polyolefins, acrylics, rayon, and cellulose acetate). Synthetic fibers tend to be more favored in carpet manufacture, as they are generally more commercially acceptable and can be used for a wider variety of applications.
Nylon is often used in carpet fiber since it is strong, easy to dye, and readily available. Nylon carpeting can be disadvantageous, however, as it generally requires various treatments in light of its susceptibility to developing static electric charges and its ease of staining. Carpets made from polyolefins, such as polypropylene, are very resistant to staining and are naturally antistatic; however, polypropylene is a more rigid and less resilient fiber and will not generally maintain its appearance or shape under prolonged or heavy use, or after repeated deformations.
Polytrimethylene terephthalate (PTT) is a favorable alternative to both nylon and polyolefins. In particular, PTT is known to provide stain resistance, static resistance, and improved dyeability while also providing a “wool-like” feel with good physical performance.
Carpeting, whether used in home or industrial applications, preferably has a high degree of fire resistance. Although PTT has many desirable properties for use in carpet fibers, the degree of fire resistance exhibited by PTT is not as favorable as other synthetic fibers. Numerous procedures have been proposed for improving the fire resistance of melt extruded filaments or fibers used in the textile industry, such as in carpet construction. One procedure to improve fire resistance has been to extrude polymeric fibers or filaments incorporating flame retardant materials into the raw polymer. This can be undesirable, however, as the incorporation of such flame retardant materials can result in finished polymers having undesirable properties, such as altered color, as well as sensitivity to heat and light. There have been attempts to overcome such problems while still improving the fire resistance of polymeric carpet fibers. For example, U.S. Pat. No. 5,024,869 proposes incorporating organic pigments and dyes, such as carbon black. Despite such efforts, however, there still remains a need for carpet materials having improved fire resistance.
Typically, in preparing carpet fiber from PTT, an extruded fiber is drawn at an elevated temperature and spun into bulk continuous filament (BCF) yarn. Preparing PTT filament by conventional spinning processes can have problems, such as frequent breakouts during spinning and drawing, dusting during production processes, and formation of yarns having low quality and poor consistency. Thus, it would also be advantageous to provide a polymeric carpet material having improved spinnability and like properties.